Downstream face of the completed Hoover Dam with the diversion tunnels in use. The outlet works and power houses are visible. A cableway spans the canyon and some transmission towers are visible high up on the canyon walls....

Aerial view of Hoover Dam after completion. The diversion tunnels are in use and the downstream face of the dam and the power houses are visible. There are transmission towers on the canyon walls above and one of...

Aerial view of Hoover Dam after completion. The reservoir (Lake Mead) is visible behind the dam along with the intake towers. Below the dam, the diversion tunnels are in use and part of the Colorado River is visible....

Aerial view of Hoover Dam and the surrounding area. Photo is actually a photograph of the area surrounding the dam with an artist's rendering of the dam, reservoir, powerhouses, and mouths of the diversion tunnels superimposed on it. It...

Aerial view of Hoover Dam and the surrounding area showing Fortification Hill in the distance. An artist's rendering of the dam, the powerhouses, the mouths of the diversion tunnels, part of the Colorado River, and Lake Mead (the reservoir) have...

Shows the construction of Hoover Dam from the downstream side. The power houses are nearly completed and one of the portals to the diversion tunnels is visible. There are trucks and buildings on the floor of the canyon....

View of construction on the Nevada power house. Framework and concrete pouring forms cover the site. Penstock tunnel openings are visible in the canyon wall in the background. Construction equipment, vehicles, temporary buildings and construction workers are seen on the...

Shows the reinforcing framework for the Arizona power house and the locations for the turbine rooms, front room galleries, and penstocks. Some buildings, trucks, tunnel openings, and construction workers are visible.

View of Hoover Dam from downstream on the Colorado River. The Nevada power house is vivisble on the left, and water is being discharged from the outlet works of the Arizona valve house on the right. The diversion tunnel portals...

View of Hoover Dam from downstream on the Colorado River. The Nevada and central power houses are seen at the base of the dam face. Water is discharged from the outlet works of the Arizona valve house on the right....

View of face of dam showing water coming out of the outlet works on the Arizona side. A bridge, a cableway above the dam, the mouths of several diversion tunnels, the Nevada power house, and construction equipment are visible. The...

Shows the face of the dam with water streaming from the outlet works on both sides. Also shows the central power house, the mouth of a diversion tunnel on the Nevada side, and Fortification Hill in the background.

Aerial view of Hoover Dam showing water spewing from the outlet works in the valve houses on both sides of the dam. The reservoir (Lake Mead) is beginning to fill above the dam. The Arizona and the central power houses...

Aerial view of Hoover Dam and the surrounding area. The outlet works are open, spewing water. The portals to three of the diversion tunnels are visible. The tops of the intake towers, the central power house, and...

Aerial view of Hoover Dam and the surrounding area. Part of the Colorado River, Lake Mead, and Fortification Hill are visible. The outlet works are open, spewing water. Several of the portals of the diversion tunnels can...

View of Hoover Dam under construction. A portal to a diversion tunnel is visible at lower left. The power houses can be seen as well as several buildings in the lower right of the photo on the cofferdam.

Expansive view of Hoover Dam showing the power houses, the waters of the Colorado River below the power houses, two of the portals to the diversion tunnels, transmission towers on the cliffs above, and a cable across the top...

This is a re-touched photo of Hoover Dam and the surrounding area. The Colorado River can be seen below the power houses. The intake towers are visible behind the downstream face. The reservoir (Lake Mead) can be...

View from a distance of Hoover Dam and the canyon. The upstream face, the power houses, and one of the portals to the diversion tunnels can be seen. There are buildings on the cofferdam and part of the...

Aerial view of the completed dam showing the downstream face and powerhouses. Lake Mead (reservoir) can be seen as it fills behind the dam. Water is spilling from the outlet works and one of the lower portals to...

Aerial view of Hoover Dam showing the upstream face, the power houses, one of the portals to a diversion tunnel, and the intake towers. Lake Mead (the reservoir) is filling and a portion of the Colorado River is also...

Panoramic view of Hoover Dam and area including Fortifiction Hill in background. The photo was taken looking towards the downstream face and shows the power houses, some of the portals to the diversion tunnels, the Colorado River, and Lake...

View of Hoover Dam and surrounding area with Fortification Hill in the background. This is a postcard with the following printed on the front: "This is an actual photo of the retouched photograph from which engraving for the...

Construction workers are seen working amid the wood and steel framework during construction of the Arizona power house. Unfinished penstock tunnel portals can be seen in the canyon wall in the background.

View of construction on the Nevada power house. The dam face is seen in the upper right. Unfinished penstock portals are seen in the canyon wall. Temporary buildings and construction equipment are seen in the cofferdam between the Nevada and...

Shows Hoover Dam construction from the top of the dam looking down. The power house, valve houses, and lower portals of the diversion tunnels are visible. Various buildings and trucks are also shown. The Colorado River is...

View of the Hoover Dam construction site in Black Canyon, showing the nearly-completed dam face and construction on the power houses in the lower cofferdam. Concrete pouring forms are seen on the tops of the power houses. Temporary buildings...

View of the Hoover Dam construction site in Black Canyon, showing the nearly-completed dam face and construction on the power houses in the lower cofferdam. Concrete pouring forms are seen on the tops of the power houses. Temporary buildings,...

View of the Hoover Dam construction site in Black Canyon, showing the nearly-completed dam face and construction on the power houses in the lower cofferdam. Concrete pouring forms are seen on the tops of the power houses. Temporary buildings, construction...

Aerial view of the Hoover Dam construction site in Black Canyon. Visible are the spillways, intake towers, dam face, diversion tunnels and construction on the power houses. Temporary buildings are seen in the cofferdam downstream of the dam face. The...

View of Hoover Dam from downstream on the Colorado River. Water is being discharged from the outlet works of the Nevada valve house on the left. Part of the Nevada power house and the central power house are seen at...

Aerial view of Hoover Dam with the outlet works on boths ides of the dam spewing water. Above the dam the reservoir (Lake Mead) is beginning to fill. Fortification Hill is in the background. the central power house...